本帖最后由 =橙子= 于 2013-4-14 05:02 PM 编辑
9. (a) Figure below shows the symbol representing an atom of sodium
nucleon no. : 23
proton no. : 11
symbol of element: Na
Based on the information given, elaborate the structure of sodium atom. your answer should include the diagram of electron arrangement and number of subatomic particles in the sodium atom. (4 marks)
-group 1 element
-diagram
-electronic configuration : 2.8.1
-valence number of electron: 1
-no. of proton = 11
-no. of electron =11
-no. of neutron =12
当然不是用简写写@@ 还有不懂可不可以用point form
(b) Organic compound X is a solid at room temperature and pressure. The melting point of X is less than 100°C.
(i) Describe a laboratory experiment to determine the freezing point of solid X. your answer should consist of following.
--> List of materials and apparatus required
--> Diagram showing the set-up of apparatus
--> Procedure of the experiment
--> Tabulation of data
--> Interpretation of data (10 marks)
这个参考书应该有
应该是naphthalene
(ii) Describe the changes occurred in the arrangement of molecules, attractive forces between the molecules and the energy content of compound X when it is cooled from 100°C to room temperature. (6 marks)
-就写 100°C 是 gas. arrangement of molecule 是什么, attractive forces
-room temperature 大概是27°C。 他是solid, arrangement 好像是orderly manner, attractive force
*大概是那样 我不是很记得了
10. (a) (i) What is a chemical formula? (1 mark) -->
课本有 (a formula shows the total no. of atom of each element in a compound )(*应该是那样)
(ii) State the qualitative and quantitative information that a chemical equation can provide. (3 marks)
-
忘记是什么
(b) (i) Name a metal which is less reactive than hydrogen in the reactivity series. (1 mark)
更正** 是用cu or ag
(ii) Describe a laboratory experiment to determine the empirical formula of the oxide of the metal named in (b)(i) above. (10 marks)
这个老师应该有教 有一种是heat,另一种是用hydrogen gas pass through 的
(c) Nowadays, most of the cars are equipped with airbags that sodium azide, NaN3. Sodium azide decomposes quickly when heated to produce nitrogen gas and sodium. The gas prodeced will expand the air bag.
Calculate the mass of sodium azide required to produce just enough nitrogen gas to inflate an air bag of volume 35 dm3 at room conditions. (relative atomic mass: N,14; Na, 23; Molar volume of gas at room conditions = 24 dm3 mol-1) (5 marks)
先写Equation, balanced
然后找no. of mol
就可以做了
不好意思哦
我忘得7788了